package hfut.example.controller;

import hfut.example.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

/**
 * 主要用于文件的上传与下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${wuyou.path}")
    private String basePath;
    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file为临时文件

        log.info(file.toString());
        //获取原始文件名
        String originalFilename = file.getOriginalFilename();
        //获取文件名后缀
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID生成文件名
        String fileName = UUID.randomUUID().toString()+suffix;

        //判断文件夹是否存在
        File dir = new File(basePath);
        if(!dir.exists()){
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(fileName);

    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){


        try {
            //输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));

            //输出流将图片写回浏览器
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len=0;
            byte[] bytes = new byte[1024];
            while ((len=fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }
}
